High speed rotary switching apparatus



Aug. 20, 1957 'c. F. MASON HIGH SPEED ROTARY SWITCHING APPARATUS 3 Sheecs-Sheet 1 Filed April 20, 1954 Fig, 3

INVENTOR. CHARLES F. MASON .F'- RNA ATTORNEYS l// ll///l///llllllIIlllIlll/IIII Aug. 20, 1957 c. F. MASON 2,803,720

HIGH SPEED ROTARY SWITCHING APPARATUS Filed April 20, 1954 5 Sheets-Sheet 2 INVENTOR.

CHARLES F. MASON A TTORNE Y3 Aug. 20, 1957 c. F. MASON 2,803,720

I HIGH SPEED ROTARY SWITCHING APPARATUS I Filed April 20, 1954 s Sheets-Sheet 5 l TO HORIZONTAL INPUT TO VERTICAL INPUT Fig. 6

INPUT IIII "x" HO Q OSCILLOSCOPE i ,0

F/g 9 -'GANGED swn'cmzs IN VEN TOR.

CHARLES F. MASON IIYII VERTICAL OSCILLOSCOPE BY TTTT INPUT A T TOR/YE Y3 HIGH SPEED ROTARY SWITCHING APPARATUS Charles Francis Mason, Willow Grove, Pa. Application April 20, 1954, Serial No. 424,532

8 Claims. (Cl. 20087) (Granted under Title 35, U. 5. Code 1952 sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the pay ment of any royalties thereon or therefor.

This invention relates to a switching apparatus, more particularly, it relates to a high speed rotary magnetic switching apparatus.

There are many applications in the field of electronics wherein it is required to actuate a number of switches alternately in a required sequence and often at high speeds. For example, a pattern can be produced on a cathode ray tube by switching a number of separate signals onto the tube at a rapid rate so that they appear to the eye to be presented simultaneously.

Previous methods for accomplishing this employ either vacuum tube switching circuits or rotary switches utilizing brush type contacts. The disadvantage of vacuum tube circuits for this purpose is that a large number of tubes and components are required and their use generates an undesirable amount of heat. When rotary switches employing brush contacts are used the brushes are subject to wear, tend to generate noise when sliding over the contacts, generate substantial heat through friction and also require an undesirable amount of force for operation. Various other types, such as magnetic switches have been designed to operate without tube circuits and brushes. These switches are somewhat satisfactory at low speeds. However, when high switching speeds are approached they are unsatisfactory because of various reasons. .For. example, magnetic switches generally utilize a cantilever type movable contact element which is subject to unwanted resonance vibrations, resulting in extraneous contacts. Again, no switch of this type is available in which the lag in the closing and opening of the contacts is sulficiently reduced to permit high speed operation. This is due in part to the mass of the movable contact element tending to reduce its response to the attracting force, and the fact that previous structures did not always provide for instantaneous introduction and removal of the full force of the magnetic field to the area adjacent the contact points. Another disadvantage of previous magnetic switching devices is the fact that ordinarily no means is provided for adjusting the clearance between the contact points while the device is in operation. This clearance is highly critical for high speed operation and it is impractical to make the required adjustment by trial and error while the switching device is stationary.

It is, therefore, an object of this invention to provide a high speed rotary switching device which is comparatively simple in construction and possesses long life.

It is another object of this invention to provide a high speed rotary switching device which operates with a minimum of noise andfriction, and which generates a minimum of heat.

It is still another object of this invention to provide a high speed rotary switching device which is subject to a minimum of lag in the operation of each individual switch.

nited States Patent It is a further object of this invention to provide a high speed rotary switching device in which the movable contact element has a high response sensitivity and operates substantially free of resonance vibrations.

It is a still further object of this invention to provide a high speed rotary switch so constructed that instantaneous introduction and removal of the full force of the attracting magnetic field to the area of the contacts is provided.

It has been found that the above and other objects are accomplished by a switching device in which at least one modified permanent horse shoe magnet is mounted on a circular disc adapted to rotate in a plane substantially parallel to a stationary disc on which are mounted members comprising the respective supporting elements for the stationary contacts and the movable contacts of one or more switch assemblies. Each movable contact supporting element is an asymmetrically shaped elongated spring of magnetically permeable material and biased to maintain the movable contact in the open position. As the magnet passes over the contact area the spring is moved in the direction of the magnet by the force of the magnetic field to contact the stationary element, and when the force is removed by rotation of the magnet the contact is broken. The magnet is of truncated triangular cross-section to provide for instantaneous introduction and removal of the full force of the magnetic field to the area of the contacts as it rotates. The spring contact element rests on an adjustment screw which permits critical adjustment of the contact spacing while the device is in operation.

The invention is best described by reference to the accompanying drawings in which:

Fig. 1 is a pictorial view of the switching device;

Fig. 2 is a sectional view of the switching device with the end plate removed;

Fig. 3 is a sectional view on the line 3-3 of Fig. 2;

Fig. 4 is a detailed side view of the switching mechanism of the device showing the magnet when it has reached a position to actuate the switch;

Fig. 5 is an end view of the switching mechanism of the device;

Fig. 6 is a pictorial view of the stationary contact and magnet;

Fig. 7 shows a pattern of wave forms produced by a four input switch when the input is a D. C. voltage;

Fig. 8 is a schematic diagram of a phase shifting circuit which is used as one input to the switching device when two ganged switches are used for generation of a circular pattern on an oscilloscope;

Fig. 9 is a schematic illustration of the application of the switching device in an oscilloscope circuit, and

Fig. 10 is an illustration of a composite pattern produced on an oscilloscope screen by means of the switching device.

Referring to Figs. 2, 3 and 4, the numeral 10 designates the outer cylindrical case to which is attached end plate 11 by screws or other suitable means. The case may be constructed of any suitable material such as aluminum, and the end plate is of plastic or other non-conductive material. The switching device is mounted on base 13. A shaft 14 carrying gear 15 for power input is rotatably mounted centrally on the end plates 11 by means of ball races 16 and 17 and held in position longiscrews 24, one of these screws serving as the electrical input to the switch mechanism. As more specifically shown in Fig. 4, stationary contact support 25 carrying stationary contact 26 on arm 27 is mounted on the end plate substantially at a right angle to the movable contact member 22. Mounting screw 23 (Fig. 5) provides the electrical output of the switch. The support 25 is bent to form arm 27 which supports the contact 26 directly over movable contact 23. For supporting permanent magnets in a plane substantially parallel to that of the movable contact members 22, a circular disc 34 of plastic or other suitable material is mounted on the shaft 14 by means of set screw 33. The magnet 32 is imbedded in the disc 30 as shown and secured in place by means of a set screw, not shown. For balancing the disc, a counterweight 34 is furnished at the required location on the disc. The rotatable disc 3% is positioned longitudinally of the shaft 14 so that as the horse-shoe magnet 32 passes the contact points, the stationary contact 26 is between the two poles of the magnet and the movable contact member 22 is in the field of the magnet. In order to adjust the clearance between the contact points 23 and 26, a set screw 35 is provided and positioned so that the bottom of movable contact member 22 rests on it. In operation, power is introduced through the gear 15 to rotate the shaft 14 and cause the magnet 32 to pass over the movable contact supporting members 22 which are attracted by the magnet to close the contacts, simultaneously completing an essentially closed magnetic circuit, as shown in Fig. 3. The speed of rotation of the shaft is adjusted according to the number of switch closures required in a given time. While the switch illustrated in Figs. 1 and 2 comprises only one magnet and four switching contacts With their inputs, any number of magnets may be mounted on the rotatable disc 30 and any number of input switches used, depending on the switching sequence required. Any number of rotatable discs carrying magnets may be ganged on the shaft, each magnet actuating its group of switches.

For a more detailed description of certain features of the invention, specific reference is made to Figs. 4, 5 and 6. Fig. ldiscloses a movable contact supporting element 22 of an unsymmetrical design for the purpose of minimizing vibration including resonance. The contact point 23 is shown located near the center of supporting member 22 but may be mounted near the S shaped or fluted end to give a modified structure less susceptible to unwanted resonant vibration. It should be understood that in addition to the asymmetrical elongated configuration provided for movable contact supporting member 22, the optimum placement of contact 23 commensurate with least resonant vibration is dependent upon factors which include the effective spring constant for supporting member 22 and the combined mass of these elements. Although the asymmetrical movable contact supporting means as depicted in Fig. 4 represents the preferred modification, a symmetrical design may be used. The position of the contact points relative to the field of the permanent bipolar magnet is shown with the magnet over the contacts. As is evident, the stationary contact is interposed between the poles of the magnet as the magnet passes over the contacts. The adjustable set screw 35 is shown slightly off center of the contact point 23. In Fig. 5 the position relationship of contact arm 27 and contact support 25 is shown. Fig. 6 shows the position relationship of the permanent bipolar magnet 2 and the stationary contact element 26 as the magnet passes over the contact element. This pictorial view of the magnet shows its truncated triangular shape. When the apex section of the magnet is mounted nearest the shaft, as shown, the construction ensures that the leading edge of the magnet will be substan tially parallel to the front edge of the movable contact supporting element 22 as the magnet starts across 'themovable contact element and that the trailing edge of the magnet will be substantially parallel to the back edge of the movable element 22 as the magnet passes beyond the movable contact supporting element. In contrast to the condition which would prevail if the magnet were rectangular, this arrangement ensures that the movable contact arm is subjected instantaneously to the full force of the magnets field, and that the entire force of the field is removed instantaneously from the movable contact arm. In addition, the provision of a movable contact supporting member having a diaphragmatic ribbonlike construction insures substantial transverse translation of this member upon magnetic attraction with the pole pieces. The inventive embodiment thus provides abrupt closing and opening of the switch in contrast to the delayed contacting and breaking which results when rectangular magnets are used, with resultant gradual introduction and removal of the magnetic field.

Various uses for the switch of the invention will be readily apparent to those skilled in the art. An applica tion in which the invention has been used is for the presentation of wave patterns on an oscilloscope in rapid succession so that the patterns appear continuous. Using a single magnet with four switches and four inputs, as illustrated in Figs. 2 and 3, a composite pattern consisting of four individual patterns is produced. For example, the output Wave for a four channel switching device with a D. C. voltage applied to it would appear as shown in Fi g. 7, the letters designating the wave forms produced by switching at each individual contact. Desired patterns may be produced by appropriate circuits and presented in rapid succession by the switch. In Fig. 8 there is shown how a phase shifting circuit is connected with two ganged switches to produce a circle as one pattern. In Fig. 9 there is shown a means of connecting a pair of ganged switches, each having four inputs, in an oscilloscope circuit to produce four patterns. A composite pattern consisting of four patternsa circle, a square, a triangle and a dotwhich can be produced by the use of the switch is shown in Fig. 10.

The invention includes the use of multiple discs and various arrangements of the magnets on either single or multiple discs with corresponding arrangement of switches to produce successive and/or simultaneous switching, as will be readily apparent to those skilled in the art. For example, a single disc may be used with all magnets on one side and in the same are or with magnets in different arcs, with corresponding banks of switches, and the magnets staggered in the latter case to obtain sequential switching if required. This same construction may be duplicated using multiple discs and corresponding banks of switches, i. e., multiple discs may be used with magnets on one side only and all magnets on all discs in the same and corresponding arcs and successive switching obtained by staggering the magnets with respect to the groups on the respective discs, or the magnets may be arranged so that corresponding switches of each group close simultaneously or some of the magnets may be mounted on different arcs on the respective discs with corresponding banks of switches, and successive switching obtained both by staggering the magnets with respect to each other on the same disc and as respects the respective groups on each disc. Simultaneous switching as required may be obtained by appropriate arrangement of magnets and switches. A further modification includes the use of one or more discs with magnets mounted on either side of the disc, with corresponding banks of switches, and the magnets on either side in identical or different arcs and arranged as necessary to obtain successive and/ or simultaneous switching. It is apparent from the above that various combinations or arrangements of discs, magnets and switches may be used and successive and/ or simultaneous switching obtained by staggering the position of the magnets and corresponding switches as necessary.

Another arrangement includes mounting a contact on the end of adjustment screw 35, or equivalent support, and another contact on the underside of movable contact 22. In this way a single pole, double throw switch is obtained.

The extra output is taken from a clamp on the section of the adjustment bolt outside the housing. This means that contact arm 22 makes co utact with the bolt or other support contact when the switch is not energized by the magnet and makes contact with contact ,26 when the switch is energized by the magnet. This arrangement also allows for a single pole, single throw switch which is biased in the closed position and which is opened by the action of the magnet. If the screw is used the desirable feature of contact spacing while the switch is in motion is still retained.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specificaly described.

I claim:

1. A high speed continuously rotating switching device for rapid cyclic closing and opening of electric switches in a predetermined sequence comprising, in combination, at least one switch having a stationary contact and a movable contact supporting member biased in the open position, said movable contact supporting member asymmetrically formed of magneticaly permeable material into a diaphragmatic ribbonlike structure to accommodate substantial transverse displacement of an intermediate portion thereof, and at least one bi-polar magnet, the respective poles of which are relatively radially disposed and mounted for continuous rotation in a common plane about a fixed axis of rotation, said movable contact supporting member spaced from and radially disposed relative to said fixed axis of rotation, the poles of said bi-polar magnet being arranged to be passed concurrently crosswise of and in juxtaposition with the intermediate portion of the movable contact supporting member, whereby said poles act substantially concurrently to effect abrupt actuation of said switch.

2. A high speed rotary switching device for rapid successive closing and opening of electric switches in a predetermined sequence, comprising in combination, at least one switch having a stationary contact member and a movable contact member of magnetic material biased in the open position; at least one permanent horse shoe magnet having a horizontal cross section of truncated triangular shape, said magnet being mounted to rotate in proximity to said movable contact member to effect closing of said switch, with the edges of the prongs leading so that the field is rotated transverse to its direction between the prongs of the magnet, the magnet being mounted with its truncated apex adjacent the center of rotation; whereby when said magnet is rotated in proximity to said switch the leading edge of the magnet is substantially parallel to the movable contact member and when the magnet passes over the movable contact member the trailing edge of the magnet is substantially parallel to the movable contact member and the biasing force of said movable member is instantaneously overcome by the attraction of the full field of the magnet to close said switch, and said switch is instantaneously opened upon the abrupt removal of the entire field of the magnet.

3. A high speed continuously rotating switching device for rapid cyclic closing and opening of electric switches in a predetermined sequence comprising, in combination, at least one switch having a'stationary contact supporting member and a diaphragmatic ribbonlike contact supporting member adapted for substantial transverse displacement and asymmetrically formed to minimize vibration, said diaphragmatic member being of magnetically permeable material and biased in the open position, at least one bi-polar magnet, the respective poles of said magnet being relatively radially disposed and mounted for continuous rotation in a common plane about a fixed axis of rotation in proximity to said diaphragmatic member, said diaphragmatic member being spaced from and radially disposed relative to said fixed axis of rotation, whereby the poles of said magnet are passed concurrently crosswise of and in juxtaposition with the diaphragmatic member to effect abrupt actuation of said switch by substantial transverse displacement of said diaphragmatic member.

4. A high speed continuously rotating switching device for rapid cyclic closing and opening of electric switches in a predetermined sequence, comprising in combination, at least one switch having a stationary contact, a stationary contact supporting member therefor, a movable contact, and an elongated movable contact supporting member of magnetically permeable resilient material therefor fixedly secured at both ends and biased to maintain said contacts in the normally open position, at least one bipolar magnet mounted radially of and disposed for continuous rotation about a fixed axis of rotation, said elongated contact supporting member spaced from and radially disposed relative to said fixed axis of rotation, the poles of said magnet being arranged in a common plane to be passed concurrently transversely of and in juxtaposition with the elongated movable contact supporting member to efiect abrupt actuation of said movable contact, said stationary contact member being located between said elongated movable contact supporting member and said magnet so that as the magnet passes adjacent the movable contact member the stationary and movable contacts are within the area of the magnet enclosed by the poles of the magnet.

5. A high speed continuously rotating switching device for rapid cyclic closing and opening of electric switches in a predetermined sequence, comprising in combination, at least one switch comprising an elongated movable contact supporting member of magnetically permeable material biased to maintain said switch in the open position and a stationary contact supporting member, an adjustable stop means to provide clearance mounted with a terminal end adjacent the underside of said movable contact member, at least one bipolar magnet mounted radially of and disposed for continuous rotation about a fixed axis of rotation, said elongated movable contact supporting member spaced from and radially disposed relative to said fixed axis of rotation, the poles of said magnet being arranged to be passed concurrently transversely of and in juxtaposition with the elongated movable contact supporting member to efiect abrupt actuation of said movable contact supporting member, said stationary contact supporting member being located between said movable contact supporting member and said magnet so that as the magnet passes through the area of the movable contact supporting member the stationary contact supporting member is within the area of the magnet enclosed by the poles of the magnet.

6. A high speed rotary switching device for rapid successive closing and opening of electric switches in a predetermined sequence, comprising in combination, at least one switch having a stationary contact member and a movable contact member of magnetic material biased in the open position; at least one permanent horse shoe magnet having a horizontal cross section of truncated triangular shape, said magnet being mounted to rotate in proximity to said movable contact member with the edges of the prongs leading so that the field is rotated transverse to its direction between the prongs of the magnet, the magnet being mounted with its truncated apex adjacent the center of rotation of the magnet; said stationary contact member being located between said movable contact member and said magnet so that as the magnetpasses through the area of the movable contact member the stationary contact member is within the area of the magnet enclosed by the prongs of the magnet.

7. A high speed continuously rotating switching device for rapid cyclic closing and opening of electric switches in a predetermined sequence, comprising in combination, a plurality of radially disposed switches, each of said switches having a stationary contact supporting member and an elongated movable contact supporting member of magnetically permeable material biased to maintain said switch in the normally open position, at least one bipolar magnet having a horizontal cross section of truncated triangular shape, the respective poles of said magnet being relatively radially disposed and mounted for continuous rotation in a common plane about a fixed axis of rotation, said elongated movable contact supporting member spaced from and radially disposed relative to said fixed axis of rotation in proximity to said elongated movable contact supporting member so that the respective poles of said magnet are passed concurrently transversely of and in juxtaposition with the elongated movable contact supporting member to effect abrupt actuation of said switch, saidrnagnet being mounted with its truncated apex adjacent the center of rotation of the magnet; said stationary contact supporting member being located between said elongated movable contact supporting member and said magnet so that as the magnet passes through the area adjacent the elongated movable contact supporting member the stationary contact member is within the area of the magnet enclosed by the poles of the magnet.

8. A high speed continuous rotating switching device for rapid cyclic successive closing and opening of electric switches in a predetermined sequence, comprising, in combination, a plurality of radially disposed switches, each of said switches having a stationary contact sup porting member and an elongated movable contact sup porting member of magnetically permeable material biased in the open position; an adjustable stop means for providing clearance mounted with a terminal end adjacent the under side of said movable contact supporting member; at least one bipolar magnet having a 3 horizontal cross section of truncated triangular shape,

the respective poles of said magnet being relatively radially disposed and mounted for continuous rotation in a common plane about a fixed axis of rotation in proximity with said elongated movable contact supporting member, said elongated movable contact supporting member spaced from and radially disposed relative to said fixed axis of rotation so that the respective poles of said magnet are passed concurrently transversely of and in juxtaposition with the elongated contact member to effect abrupt actuation of said switch, the magnet being mounted with its truncated apex adjacent the center of rotation of the magnet; said stationary contact supporting member being located between said elongated movable contact supporting member and said magnet so that as the magnet passes through the area of the elongated movable contact supporting member the stationary contact member is within the area of the magnet enclosed by the poles of the magnet.

References Cited in the file of this patent UNlTED STATES PATENTS 878,467 Orswell Feb. 4, 1908 958,509 Lawton May 17, 1910 1,529,470 Dowd Mar. 10, 1925 1,530,936 Greenwood Mar. 24, 1925 1,706,523 Churcher Mar. 26, 1929 1,870,032 Young et a1. Aug. 2, 1932 2,283,340 Ray May 9, 1942 2,310,138 Whittaker Feb. 2, 1943 2,310,357 Edelman Feb. 9, 1943 2,448,779 Crise Sept. 7, 1948 FOREIGN PATENTS 545,818 Great Britain June 15, 1942 720,957 France Dec. 12, 1931 

